Vault Toilets

Not to be confused with "outhouses" which are simply holes in the ground with some sort of shelter above with a cut out for a commode. The waste simply fills the hole and the building is then moved.

Vault Toilets are actual tanks in the ground and a structure is built over top. These are the preferred rest facilities at a lot of campgrounds. The tanks are water tight, with no drainage and must be pumped out.